A 34-year-old man was admitted because of a three-month history of cough, dyspnea, fever, progressive bilateral cavitary lung lesions, and a lymphohistiocytic infiltrate. He received corticosteroids, but his symptoms persisted. The lung lesions increased in size, and some cavitated, necessitating readmission to the hospital and a diagnostic procedure.

A 71-year-old woman with Crohn's disease, who had been receiving treatment with mercaptopurine and infliximab, had fatigue, blurred vision, headache and mood changes, and an inguinal mass. She had a sudden onset of left-sided weakness; brain imaging disclosed a mass, and she was transferred to this hospital. Shortly after admission, she had a seizure and became unresponsive.

A 68-year-old man noted a rash followed by periorbital swelling and muscular weakness. Several months before his hospital admission, he had had involuntary weight loss, and his physician had noted anemia. The results of an evaluation for gastrointestinal cancer were negative. Abdominal computed tomography disclosed a mass involving the spleen and retroperitoneum. A diagnostic procedure was performed.

An 81-year-old man was admitted to the hospital because he had had cough and fever for two weeks and had recently become confused. He had had chronic lymphocytic leukemia for six years. His mental status continued to deteriorate, with coma and respiratory arrest, and he died on the 12th hospital day.